The Tychonic system, proposed by Tycho Brahe in the late 16th century, is a model of the solar system that combines elements of both the geocentric and heliocentric theories. In this system, the Earth is at the center, while the Sun and the Moon orbit the Earth. The other planets, including Mars, Jupiter, and Saturn, orbit the Sun. This model was developed as a compromise between the prevailing Ptolemaic system, which placed the Earth at the center, and Copernicus' heliocentric model, which positioned the Sun at the center. The Tychonic system was significant in the history of astronomy, influencing later scientists like Johannes Kepler.